RFR: 8337938: ZUtils::alloc_aligned allocates without reporting to NMT [v2]

[Joel Sikström]

> Replaces usage of posix_memalign/_aligned_malloc with os::malloc and manual alignment to report memory usage to NMT. Manually aligning the memory makes the returned address unfreeable by malloc (as clarified by the added comment), which is reasonable since the memory used by ZUtils::alloc_aligned is never freed.
> 
> Tested with tiers 1-3.

Joel Sikström has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Merge branch 'master' into zgc_zutils_alloc_aligned
 - Updated copyright years
 - Remove trailing whitespace
 - 8337938: ZUtils::alloc_aligned allocates without reporting to NMT

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/20523/files
  - new: https://git.openjdk.org/jdk/pull/20523/files/cb942b1b..d227e0de

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20523&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20523&range=00-01

  Stats: 551 lines in 25 files changed: 357 ins; 77 del; 117 mod
  Patch: https://git.openjdk.org/jdk/pull/20523.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20523/head:pull/20523

PR: https://git.openjdk.org/jdk/pull/20523